Question

Se considera sirul de multimi : A1 = {1} , A2 = {2,3,4} , A3 = {5,6,7,8,9,}etc , determinati multimea A 2018

Dau coroana

Answer 1

fiecare multime An contine 2n+1 elemente

incepand de la (n-1)²+1 pana la n²...cam complicat de demonstrat, mai ales la gimnaziu ..poti verifica peexemplele date sau, la liceu, prin inductie completa

deci A2018= {2017²+1;2017²+2;....;2018²}